Table 210.21

[Djelite]

Hi on table 210.21 it states 15a and 20a receptacles can be connected to a 20a cb. Mike holts states that this is possible because they are identical devices inside minus the face plate. How come the same is also true for 40a 50a receptacle s?

 

[d0nut]

Can you show a photo or NEMA configuration for your 40A receptacle?

 

[Djelite]

Can you show a photo or NEMA configuration for your 40A receptacle?

Im asking if the 40a and 50a receptacle are internally identical like the 15 and 20?. Why would the chart allow 2 receptacles of different rating to be protected by the same ocpd

 

[d0nut]

Look for a standard 40A NEMA receptacle configuration and you will understand why the chart allows 50A receptacles to be fed from 40A circuits.

 

[retirede]

Im asking if the 40a and 50a receptacle are internally identical like the 15 and 20?. Why would the chart allow 2 receptacles of different rating to be protected by the same ocpd

They’re not only internally identical, they’re also externally identical.

 

[LarryFine]

Im asking if the 40a and 50a receptacle are internally identical like the 15 and 20?.

Yes; even most 30a dryer plugs and receptacles use 50a-capable parts.

 

[infinity]

Im asking if the 40a and 50a receptacle are internally identical

There are no 40 amp receptacles only 50's. If you have a 40 amp circuit you would use a single 50 amp receptacle.

 

[quantum]

Im asking if the 40a and 50a receptacle are internally identical like the 15 and 20?. Why would the chart allow 2 receptacles of different rating to be protected by the same ocpd

Hi on table 210.21 it states 15a and 20a receptacles can be connected to a 20a cb. Mike holts states that this is possible because they are identical devices inside minus the face plate. How come the same is also true for 40a 50a receptacle s?

Since it's only allowed when there is more than 1 receptacle on the circuit, I've always assumed a duplex or two singles (2 × 15A) will spread the load and make it safe for a 20A branch circuit.